Image from the Biodiversity Heritage Library.
Contributed by Museum of Vertebrate Zoology, University of California, Berkeley.
| www.biodiversitylibrary.org
Transcription
Remsen,
J.V.
1975
Merlin
Falco columbarius
Jan.15 Sacramento NWR, Glenn Co., Calif.: li
Apr.16 Alameda Beach, Alameda Co., Calif: lā chasing shorebirds. Before we
even saw the Merlin, it was very obvious from the alarm calls of the
shorebirds that a bird-eater was approaching. It rocketed along the
beach, flying low over the sand, and suddenly swerved into the middle
of a sandpiper flock, but missed. It continued down the beach and
dove into another flock but missed again. It then reversed its path
and flew more slowly upwind back up the beach and disappeared.
About 5 minutes later it again dashed into a sandpiper flock,
coming in very low over the beach, but apparently missed and we
lost sight of him. The flight speed was very impressive, especially
when it dove at a flock. As soon as the Merlin was detected,
all the sandpipers formerly spread out on the mudflat formed
tight bunches which persisted until the Merlin left ā good anecdotal
evidence for those who believe predator-avoidance to be
the causal factor in flocking.
Nov.2 Salinas River Valley, Monterey Co., Calif.: I sitting in field behind Smydouski Pond.
Dec.21 San Diego area, San Diego Co., Calif: 2 im. in stubble fields in Tijuana Valley.
One chased the other. One actually perched on a telephone wire, which
they are not supposed to do. The fields had 200+ Savannah Sparrows